An Organic Light-Emitting Diode (OLED) display screen has been accepted as one of the next generation of display technologies with a promising prospect due to its advantages of a small thickness, a low weight, a wide angle of view, active light-emission, a consecutively tunable color of light emission, a low cost, a high response speed, low power consumption, low drive voltage, a wide range of operating temperature, a simple production process, high efficiency of light emission, a flexible display, etc.
Films at respective functional layers of the OLED display are generally formed in a vapor-plating process and a solution process. The vapor-plating process has been applied to the OLED display with a small size, and this process has been applied at present to massive production; and the films at the respective functional layers of the OLED display are generally formed in the solution process through inkjet printing, coating using a spray, spin-coating, grid printing, etc., where the technology of inkjet printing has been recognized as an important approach for massive production of the OLED with a large size due to its high utilization ratio of materials, and a large-size implementation.